Epilation head for motor-powered epilating appliances

ABSTRACT

The invention concerns a hair-plucking head for a motor-driven depilation appliance. The head has a gripping device with at least two diametrically opposed spring-biased gripper jaws which can be pressed against the inside of a hollow cylinder mounted in the casing of the appliance. The jaws operate in conjunction with a control element disposed equiaxially with the cylinder axis. The appliance also has a transmission link between the motor and the cylinder and/or the control element. The jaws are mounted to pivot on pins located inside the cylinder and driven by the control element and a lever assembly.

This invention relates to an epilation head for motor-powered epilatingappliances, comprising a hollow cylinder which is at least in partenclosed by the appliance casing and whose working surface to be placedin contact with the skin is defined by its end surface, with a grippingdevice mounted in the hollow cylinder and comprised of at least twodiametrically opposed spring-loaded gripping members adapted to be urgedinto gripping engagement with the inner surface of the hollow cylinderand being operatively associated with a control element disposedequiaxially with the cylinder axis, with a transmission link beingprovided between the drive motor and the hollow cylinder and/or thecontrol element.

An epilating appliance of the aforementioned type is described in Germanpatent application No. DE 39 22 949. In the epilation head structuredescribed therein in several variants, the gripping members are mountedon the free ends of leaf springs having their other ends attached to theinner surface of the hollow cylinder. The control element which effectsthe opening or closing movement of the gripping members is configured asa cam acting below the gripping members directly on the leaf springs.

These provisions of the invention assure a precise sequence of motion ofthe gripping members. Because of the possibility of varying the leverratios, the energy balance can be favorably affected with regard to theforces to be generated for opening or closing the gripping members andthe maintaining of the gripping force in the closed position, as well aswith regard to the forces of friction and mass inertia.

The axle arrangement is especially advantageous if it is consideredimportant to have a largely free choice regarding the lever lengths inthe direction of the geometrical axis of the cylinder.

A particular axle arrangement affords the advantage of accomplishing anearly uniform opening space as the gripping members open or, wherenecessary, an opening space enlarged in the form of a wedge bydisplacement of the fulcrum of the gripping members, thus facilitatingthe guiding of the hairs into the gripping space. In addition, itenables the length of the epilation head to be reduced appreciably inthe direction of the cylinder axis.

When the gripping members are normally urged into their closed position,the opening movement occurring by the control element in opposition tothe spring force. Accordingly, only this action requires energy to beexpended. In particular the opening movement can be accelerated bysuitably forming the control element (cam or cam disk).

A particular operating mechanism for the gripping members combines theadvantages of a particularly straightforward construction with quietrunning and energy savings. Conversely to the embodiments previouslyreferred to, the supply of energy for operation of the gripping membersin an appreciable amount is only necessary in the range of closedgripping members, while the functions "Open--Keep Open--Close" requireforces of friction and mass inertia to be overcome which, however, canbe maintained at a low level by technical means known in the art.

Another advantageous embodiment of an epilation head has a mechanism formovement of the gripping members which incorporates essential advantagesof the variants previously described, including: Full closing force overthe entire range of the closing angle of the control element at lowlevels of energy consumption. Energy for operation of the grippingmembers is needed only for the duration of the closing action, that is,the plucking action. It is proportional to the actual gripping forcewhich, in turn, is directly dependent on the force of the spring in thegripping member-and-lever assembly and can be easily held within closelimits. The additional spring travel made possible due to the restrictedrelative movability of the two components is only needed to compensatefor manufacturing tolerances, being irrelevant in respect of a forceincrease.

Embodiments of the present invention are illustrated in the accompanyingdrawings.

In the drawings,

FIG. 1 is a view of an epilating appliance illustrating partly insection an epilation head and schematically the components in theappliance casing;

FIG. 2 is a longitudinal sectional view of the epilation headillustrating a first embodiment thereof;

FIG. 3 is a longitudinal sectional view of the epilation headillustrating a second embodiment thereof;

FIG. 4 is a longitudinal sectional view of the epilation headillustrating a third embodiment thereof;

FIG. 5 is a top plan view of the epilation head of FIG. 4; and

FIG. 6 is a longitudinal sectional view of the epilation headillustrating a fourth embodiment thereof.

The epilating appliance illustrated in FIG. 1 is essentially comprisedof a casing 1 accommodating a motor 2 illustrated schematically whichmay be an electric motor supplied with energy from primary or secondarycells or directly from the mains supply, or alternatively, a springmotor.

The casing 1 further embraces part of a hollow cylinder 3 which is partof the epilation head and may be fixedly mounted in the interior of thecasing 1 or, alternatively, rotatably carried therein, as described inpatent application No. DE 39 22 949.

Coaxially with the geometrical axis A of the hollow cylinder 3, a shaft4 is rotatably mounted in the casing 1, the shaft being driven by amotor 2 through a transmission mechanism 5 illustrated schematically;optionally, this transmission mechanism 5 may also be used for drivingthe hollow cylinder 3. Where a stationary axle is used in lieu of theshaft 4, the link to the transmission mechanism 5 is omitted.

In the interior of the hollow cylinder 3, diametrically opposed grippingmembers 7 are pivotally mounted on fixed axles 6, the gripping membersbearing with one end against an inner surface 9 of the hollow cylinder 3under the action of a spring 8, while their other ends cooperate vialever arms 10 with a control element 11 which may be configured as a cam12 and is mounted on the shaft (or axle) 4.

For convenience of illustration, FIG. 1 shows only one half of thediametrically opposed gripping member-and-spring assembly arranged inmirror-image relationship to each other.

The periphery 13 of the hollow cylinder 3 with which the epilatingappliance is placed on the skin forms the end surface of the epilationhead, thus defining its working surface B.

The various possibilities of locating or driving the hollow cylinder 3and the shaft 4 of the control element 11 being described in patentapplication No. DE 39 22 949 initially referred to, they will not beexplained in greater detail in the following.

In the epilation head illustrated in FIG. 2, the hollow cylinder 3 hasat its bottom a transverse partition 14 through which the shaft (oraxle) 4 of the control element 11 extends which in this embodiment isconfigured as a cam 12. Above the cam 12, when viewed in the directionof the end surface of the hollow cylinder 3, the hollow cylinderreceives two axles 6 arranged at right angles and in a mirror-imagerelationship to the cylinder axis A, with two diametrically opposedgripping members 7 being pivotally mounted thereon. In the direction ofthe casing interior, the gripping members 7 are provided with lever arms10 having free ends 15 acting in conjunction with the cam 12. Seatedbetween two gripping members 7 is a compression spring 8 in the form ofa bending leg spring urging the gripping members 7 into the closedposition by abutting engagement with the inner surface 9 of the hollowcylinder 3 in the upper area thereof.

For the duration of a cycle of operation, the gripping members 7 areurged into the open position by the revolving or stationary cam 12engaging the lever arms 10 and, on disengagement of the cam 12, arepivoted back to their closed position by the action of the spring 8. Afavorable mechanical construction is realizable by the provision of asuitable lever ratio of the gripping members 7 formed by the relativedistance of the pivot axle 6 and the point of force application to thecam on the one side, and the gripping surface in the upper area 16 ofthe hollow cylinder 3 on the other side. Because the gripping members 7are opened by the cam 12 whereas they are closed by spring force, theclosing movement may be performed at an extremely high speed byproviding the cam 12 with a suitable profile. This allowscorrespondingly longer periods for the hair engaging and pluckingactions during a working cycle, and the spring-actuated gripping members7 experience a high initial closing force whereby a secure grip upon thehairs is assured.

In the variants of the epilation head subsequently described, theconfigurations of the hollow cylinder 3 and the shaft or axle 4 areunchanged, being identified by like reference numerals. The variant ofthe epilation head shown in FIG. 3 includes a hollow cylinder in whichtwo axles 6 are arranged in the same manner as in FIG. 2 and havepivotally mounted thereon gripping members 20 engaging the inner surface9 of the hollow cylinder 3 in the upper area 16 thereof. The shaft (oraxle) 4 extending through the transverse partition 14 of the hollowcylinder 3 carries at its free end the control element 11 which in thisembodiment is configured as a cam disk 21. Firmly embedded in thegripping members 20 are leaf springs 22 having spherical sliding means23 at their respective free ends for engagement in the control groove 24of the cam disk 21.

The leaf spring 22 thus combines in a single component the function ofspring action with the function of the transmission of motion from thecontrol element 11 to the gripping member 20, while in the embodiment ofFIG. 2 these two functions were distributed to two components. In aworking cycle, with the entire system rotating, the cam disk 21 which isat rest or rotating at a suitable speed causes pivotal movement of thegripping members 20 under the action of the bending spring 22.Subsequent to the closing of the gripping space between the grippingmembers 20 and the meeting area 16 of the inner surface 9 of the hollowcylinder 3, pressing over of the leaf springs 22 produces the grippingforce for securely holding the hairs and assuring the grip for theduration of the necessary angle of rotation.

In the epilation head of FIGS. 4 and 5, the hollow cylinder 3accommodates two axles 25 extending parallel to the geometrical axis Aof the cylinder and having pivotally mounted thereon the grippingmembers 26, such that the pivotal movement occurs in a directionparallel to the working surface B of the epilation head. FIG. 4 showsonly one axle 25. A helical spring 27 seated between the two grippingmembers 26 urges the two gripping members 26 into the closed position inwhich they are in engagement with the inner surface 9 of the hollowcylinder 3. The gripping members 26 are provided with respective leverarms 28 cooperating with the control element 11 mounted on the shaft (oraxle) 4, the control element being in this embodiment of a cup-shapedconfiguration having an inner surface 29 serving as a control camagainst which the lever arms 28 abut at least during the pivotalmovement of the gripping members 26.

With the gripping members 26 arranged in this manner and the clearancebetween the members dimensioned as herein provided, a nearly uniformopening space results between the gripping members 26 and the innersurface 9 of the hollow cylinder 3. Where necessary, however, an openingspace enlarged in the form of a wedge may be accomplished by relocatingthe pivot axles 25 from the position shown in FIG. 5 while thedimensions of the gripping members 26 are maintained, in order tofacilitate the guiding of the hairs to be plucked into the grippingspace.

The embodiment of the epilation head illustrated in FIG. 6 equallyincludes a transverse partition 14 through which the shaft (or axle) 4extends, and two axles 6 disposed in the upper portion of the hollowcylinder 3 at right angles to the geometrical axis A of the hollowcylinder 3. Mounted on these axles are both gripping members 30 andseparate lever arms 31 initially independent thereof, thus allowingtheir relative rotational movement. The lever arms 31 have at their freeends respective spherical sliding members 32 formed integral therewithand engaging in the control groove 33 of a cam disk 34 mounted on theshaft (or axle) 4, the cam disk representing the control element 11 inthis embodiment.

The gripping members 30 have each a hood-type extension 35 embracingpart of the lever arms 31. Seated between the two components is a spring36 in the form of a bending leg spring embracing the associated axle 6and urging the gripping members 30 and the associated lever arms 31apart until the lever arms 31 are in abutting engagement with recessesproviding abutment stops 37 in the hood-shaped extension 35.

In this abutment position which is illustrated in FIG. 6 and in whichthe gripping space between the gripping members 30 and the inner surface9 of the hollow cylinder 3 is closed, the assembly comprising thegripping members 30, the spring 36 and the lever arm 31 constitutes acomplete functional unit operated by the control groove 33 of the camdisk 34 as follows:

Operating in synchronism with the relative movement of the cam disk 34and the lever arm 31, the gripping space will open from the closedposition shown in the drawing up to a maximum width which is maintainedconstant over an angle of rotation determined by the profile of thecontrol groove 33; the succeeding closing action is performed throughthe lever arm 31 until the gripping members 30 have again reached theclosed position shown. As the closing movement proceeds, the lever arm31 moves away from the abutment stop 37 in the direction of thegeometrical axis A of the hollow cylinder 3, with the gripping members30 maintaining the full closing force on the gripping space over theentire range of the closing angle. In the further sequence, the controlelement 11 returns the lever arm 31 into engagement with the abutmentstop 37, starting a new working cycle.

We claim:
 1. An epilating appliance comprising a casing, an epilationhead and a drive motor operatively attached to said epilation head, saidepilation head comprising hollow cylinder structure which is at least inpart enclosed by the appliance casing, said cylinder structure having aninner surface and an open end that defines a working surface (B) to beplaced in contact with the skin, axle structure in said hollow cylinderstructure, gripping structure mounted in said hollow cylinder structureand comprised of at least two diametrically opposed gripping memberspivotally mounted on said axle structure and adapted to be urged intogripping engagement with said inner surface of said hollow cylinderstructure, control structure disposed equiaxially with a geometricalaxis (A) of said cylinder structure, a transmission link coupled to saiddrive motor for producing relative movement between said hollow cylinderstructure and said control structure, and a lever arrangement responsiveto said control structure and coupled to said gripping members fordriving said gripping members.
 2. The epilating appliance of claim 1wherein said axle structure is disposed at right angles to saidgeometrical axis (A) of said cylinder structure.
 3. The epilatingappliance of claim 1 wherein said axle structure is disposed parallel tosaid geometrical axis (A) of said cylinder structure.
 4. The epilatingappliance of claim 1 and further including common compression springstructure disposed between said two opposed gripping members, andwherein each said gripping member includes a lever arm of said leverarrangement that extends parallel to said geometrical axis (A) andcooperates with said control structure.
 5. The epilating appliance ofclaim 4 wherein said axle structure is disposed at right angles to saidgeometrical axis (A) of said cylinder structure.
 6. The epilatingappliance of claim 5 wherein each said lever arm has a free end, andsaid control structure includes a cam member for positive engagementwith said free ends of said lever arms.
 7. The epilating appliance ofclaim 4 wherein said axle structure is disposed parallel to saidgeometrical axis (A) of sad cylinder structure.
 8. The epilatingappliance of claim 1 wherein each said gripping member is provided witha leaf spring extending substantially parallel to said geometrical axis(A) and serving as a lever arm, each said spring having a free endcooperating with sad control structure.
 9. The epilating appliance ofclaim 8 wherein said axle structure is disposed at right angles to saidgeometrical axis (A) of said cylinder structure.
 10. The epilatingappliance of claim 1 wherein each said gripping member has separatelever arm structure that is pivotally mounted on said axle structure andis relatively movable within limits, and a spreader spring is seatedbetween each said lever arm structure and its associated grippingmember.
 11. The epilating appliance of claim 10 wherein said axlestructure is disposed at right angles to said geometrical axis (A) ofsaid cylinder structure.
 12. The epilating appliance of claim 1 whereingripping structure includes a lever arm associated with each saidgripping member, each said lever arm has a free end, and said controlstructure includes a cam member for positive engagement with said freeends of said lever arms.